// Call this function AFTER operation.
public void NewState(DrawingCanvas drawingCanvas)
{
// Keep objects state after operation.
FillList(drawingCanvas.GraphicsList, ref listAfter);
}
public UndoManager(DrawingCanvas drawingCanvas)
{
this.drawingCanvas = drawingCanvas;
ClearHistory();
}
/// <summary>
/// Handle mouse down.
/// Start moving, resizing or group selection.
/// </summary>
public override void OnMouseDown(DrawingCanvas drawingCanvas, MouseButtonEventArgs e)
{
commandChangeState = null;
wasMove = false;
Point point = e.GetPosition(drawingCanvas);
selectMode = SelectionMode.None;
GraphicsBase o;
GraphicsBase movedObject = null;
int handleNumber;
// Test for resizing (only if control is selected, cursor is on the handle)
for (int i = drawingCanvas.GraphicsList.Count - 1; i >= 0; i--)
{
o = drawingCanvas[i];
if (o.IsSelected)
{
handleNumber = o.MakeHitTest(point);
if (handleNumber > 0)
{
selectMode = SelectionMode.Size;
// keep resized object in class member
resizedObject = o;
resizedObjectHandle = handleNumber;
// Since we want to resize only one object, unselect all other objects
HelperFunctions.UnselectAll(drawingCanvas);
o.IsSelected = true;
commandChangeState = new CommandChangeState(drawingCanvas);
break;
}
}
}
// Test for move (cursor is on the object)
if (selectMode == SelectionMode.None)
{
for (int i = drawingCanvas.GraphicsList.Count - 1; i >= 0; i--)
{
o = drawingCanvas[i];
if (o.MakeHitTest(point) == 0)
{
movedObject = o;
break;
}
}
if (movedObject != null)
{
selectMode = SelectionMode.Move;
// Unselect all if Ctrl is not pressed and clicked object is not selected yet
if (Keyboard.Modifiers != ModifierKeys.Control && !movedObject.IsSelected)
{
HelperFunctions.UnselectAll(drawingCanvas);
}
// Select clicked object
movedObject.IsSelected = true;
// Set move cursor
drawingCanvas.Cursor = Cursors.SizeAll;
commandChangeState = new CommandChangeState(drawingCanvas);
}
}
// Click on background
if (selectMode == SelectionMode.None)
{
// Unselect all if Ctrl is not pressed
if (Keyboard.Modifiers != ModifierKeys.Control)
{
HelperFunctions.UnselectAll(drawingCanvas);
}
// Group selection. Create selection rectangle.
GraphicsSelectionRectangle r = new GraphicsSelectionRectangle(
point.X, point.Y,
point.X + 1, point.Y + 1,
drawingCanvas.ActualScale);
r.Clip = new RectangleGeometry(new Rect(0, 0, drawingCanvas.ActualWidth, drawingCanvas.ActualHeight));
drawingCanvas.GraphicsList.Add(r);
selectMode = SelectionMode.GroupSelection;
}
lastPoint = point;
// Capture mouse until MouseUp event is received
drawingCanvas.CaptureMouse();
}
// Create this command BEFORE operation.
public CommandChangeState(DrawingCanvas drawingCanvas)
{
// Keep objects state before operation.
FillList(drawingCanvas.GraphicsList, ref listBefore);
}
/// <summary>
/// Handle mouse move.
/// Se cursor, move/resize, make group selection.
/// </summary>
public override void OnMouseMove(DrawingCanvas drawingCanvas, MouseEventArgs e)
{
// Exclude all cases except left button on/off.
if (e.MiddleButton == MouseButtonState.Pressed ||
e.RightButton == MouseButtonState.Pressed)
{
drawingCanvas.Cursor = HelperFunctions.DefaultCursor;
return;
}
Point point = e.GetPosition(drawingCanvas);
// Set cursor when left button is not pressed
if (e.LeftButton == MouseButtonState.Released)
{
Cursor cursor = null;
for (int i = 0; i < drawingCanvas.Count; i++)
{
int n = drawingCanvas[i].MakeHitTest(point);
if (n > 0)
{
cursor = drawingCanvas[i].GetHandleCursor(n);
break;
}
}
if (cursor == null)
{
cursor = HelperFunctions.DefaultCursor;
}
drawingCanvas.Cursor = cursor;
return;
}
if (!drawingCanvas.IsMouseCaptured)
{
return;
}
wasMove = true;
// Find difference between previous and current position
double dx = point.X - lastPoint.X;
double dy = point.Y - lastPoint.Y;
lastPoint = point;
// Resize
if (selectMode == SelectionMode.Size)
{
if (resizedObject != null)
{
resizedObject.MoveHandleTo(point, resizedObjectHandle);
}
}
// Move
if (selectMode == SelectionMode.Move)
{
foreach (GraphicsBase o in drawingCanvas.Selection)
{
o.Move(dx, dy);
}
}
// Group selection
if (selectMode == SelectionMode.GroupSelection)
{
// Resize selection rectangle
drawingCanvas[drawingCanvas.Count - 1].MoveHandleTo(
point, 5);
}
}
/// <summary>
/// Set cursor
/// </summary>
public override void SetCursor(DrawingCanvas drawingCanvas)
{
drawingCanvas.Cursor = HelperFunctions.DefaultCursor;
}
/// <summary>
/// Detete All again
/// </summary>
public override void Redo(DrawingCanvas drawingCanvas)
{
drawingCanvas.GraphicsList.Clear();
}
public override void OnMouseUp(DrawingCanvas drawingCanvas, MouseButtonEventArgs e)
{
newPolyLine = null;
base.OnMouseUp(drawingCanvas, e);
}
public abstract void SetCursor(DrawingCanvas drawingCanvas);
public abstract void OnMouseUp(DrawingCanvas drawingCanvas, MouseButtonEventArgs e);
public abstract void OnMouseMove(DrawingCanvas drawingCanvas, MouseEventArgs e);